Plunger guide for solenoids



y 1951 RSCHELL 2,562,439

PLUNGER GUIDE' FOR SOLENOIDS Filed Nov. 6, 1948 54 92 INVENTOR.

P414 pmezi.

Patented July 31, 1951 PLUNGER GUIDE FOR SOLENOIDS Pall Iowa

Sehell, Elkhart, Ind., alllgnor to Penn Electrie Switch 60., Goshen,Ind., a corporation of Application November 6, 1948, Serial No. 58.639

This invention relates to a guide for the plunger of a solenoid. theguide being removably positioned in relation to the core for thesolenoid coil whereby the coil may be pre-wound and then inserted in thecore after which the guides are positioned inside the coil and the coilwith its core and guides are then ready to receive the plunger. I

One object of the invention is to provide an arrangement which permitsthe plunger guides to be removably positioned in relation to thesolenoid core so that coils can be interchanged if desired and theinitial assembly of the entire solenoid facilitated by an arrangementwhich permits the coil to be pro-wound independent of the core and theninserted in the core after it is wound, the association of the guideswith the core being such as to permit rigid mounting of the guides inthe core yet also permit them to be later removed without the necessityof removing any fastening elements.

Another object is to provide a solenoid core with a frame designed tocoact with plunger uides in such manner that the guides are received inthe frame at one end and are provided with hook-like fingers to coactwith the frame at the other end so that both ends are fixed in supportedposition.

A further object is to provide a spring finger projecting from theplunger guide for coaction with the core frame to retain the guide inposition except when the finger is depressed to permit removal of theguide.

With these and other objects in view, my invention consists in theconstruction, arrangement and combination of the various parts of mydevice whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claim and illustrated in theaccompanying drawings, wherein:

Figure 1 is a front elevation of a motor starter switch showing myinvention in connection therewith. v

Figure-2 is a plan view of the solenoid and its plunger and. guidesapart from the motor start- 1m switch.

Figure 3 is a sectional view on the line 3-3 of Figure 1.

Figure 4 is a perspective view of one of the plunger guides.

Figure 5 is an inside elevation thereof, and

Figure 6 is a perspective view oi the solenoid core and the core frameshowing one 00f the plunger guides in position for assembly in relationthereto.

On the accompanying drawing, I have used the reference character MS toindicate in general a motor starting switch as shown in my copendingapplication, Serial No. 695,336, filed September 6, 1946, now abandoned.The motor starting switch has stationary contacts Ill and movablecontacts II. The contacts l2 are carried by a block of insulation l4adapted to be connected with the plunger of the solenoid. Suitablebrackets it connect with the motor starting switch MS and with a backplate It.

The solenoid here involved comprises a coil II, a rectangular core 20formed of laminae and a a plunger 22 also laminated, in addition to theplunger guides which will be described specifically. The core 20 asillustrated in Figure 6 is not a complete rectangle but open at one endto receive the plunger I! as in Figure 3, the plunger being normally inthe lowered position illustrated and adapted to be raised by magneticattraction when the coil is is energized until the upper end oi. theplunger strikes the upper leg of the core 20 in the usual manner.

The core laminae 20 are stacked between a pair of similar frame plates22, the assembly being riveted together as at 24. Openings 26 extendthrough both core plates 22 and the laminae 20 to receive mountingscrews 20 which mount the core on the base plate l'l.

Each core plate 22 is rectangular in shape and has an outwardly oifsetplunger guide receiving portion 30 at one end and a, similar guidereceiving portion 32 at the other end. The portion 32 is notched asillustrated at 34.

The plunger guides are shown best in Figures 4, 5 and 6. They hear thereference character G. Each guide is channel shaped in cross sectionhaving a web 36 and flanges 38. The flanges it are cut back or notchedat 40 at one end and at 42 at the other end. The end at 42 has a reversebent lip 44 and adjacent the lip a spring finger it is bent slightly outof the plane of the web It.

Adjacent the other end of the guide a pair of beads 48 and a projection50 are provided for defining a guide channel for the plunger andproperly guiding it without undue friction along the entire surface ofthe guide G. The guides G are inserted through the guide receivingportions 32 and 30 successively as suggested in Figure 6 and asillustrated in Figure 3. In Figure 3 the right hand guide is in itsfinal position, whereas the leit hand guide is being inserted to itsfinal position. In such final position the notches ii engage inthe guidereceiving portion II and it will be noted in Figure 4 that the long sideof the notch is at a slight angle which serves to guide the entering'endof the guide G into the portion II and tighten it therein.

In the final position of the guide as at the right side of Figure 3, thelip 44 engages the guide receiving portion 32 oi" the core frame tosecurely position this end of the guide G. The lip 44 is at this timeunder slight spring tension and as soon as the lower end of the finger4! passes the portion 32 it will snap from the position at the left sideof Figure 3 to the position at the right side thereof and thereafterkeep the guide G permanently in its mounted position.

The guide however can be removed by pressing the finger ll inwardly toclear the portion 32 as when necessary for dis-assembling the solenoidfor changing the coil thereof.

With the arrangement disclosed the core and frame assembly 2022 shown inFigure l is adapted to receive the solenoid coil it after the coil hasbeen pre-wound on a form in a winding machine. It is unnecessary to windthe coil in position in the core as it can be merely placed in the coreof Figure 6 before the plunger guides G are inserted.

After the guides are inserted to their assembled position the plunger I1is slid into position in the guides and the side plates i which areriveted to the laminated plunger are guided by the channel shaped guidesG with the beads 49 and the projection 50 serving as the guiding pointsat the upper end of the plunger. The side plates II are then connectedto the contact block I! as by a screw 52 and in the down position of theplunger the block engages the upper surface of the upper leg of the core2| to act as a stop. A cross piece it on the lower end of the plungeracts as a means to aid in carrying the flux across the air gaps betweenthe plunger and the core. Engagement of the plunger with the lowersurface of the upper leg of the core is the means to tor starting switchor with any element to be operated by the plunger.

The guides are mounted so that they can be readily removed if that isdesirable as for instance when replacing a bumed-out coil or changingcoils. The arrangement also makes possible the assembly of the solenoidin a minimum of time.

Some changes may be made in the construction and arrangement of theparts of my device without departing from the real spirit and pur poseof my invention, and it is my intention to cover by my claim anymodified forms of structure or use of mechanical equivalents which maybe reasonably included within their scope.

I claim as my invention:

In a solenoid construction, a core. frame plates connected on oppositesides thereof and provided with guide receiving portions, channel-shapedplunger guides removably received in said portions, one of said guidereceiving portions defining a passageway to receive one end of a guideand said end having its flanges partially cut away at an angle toproduce a wedging action of said plunger guide in said guide receivingportion, said guides having return bent convergent lips at their otherends. the other of said guide receiving portions being received in saidreturn bent lips and resiliently confined between them and the opposingsurfaces of said guides. said guides having U-shaped slots to providelocking tongues comprising those portions of the guides between the legsof the U-shaped slots. said locking tongues being cooperable with saidother of said guide receiving portions.

PAUL SCHELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 533,385 Tweedale Jan. 29, 18951,371,210 King Mar. 8, 1921 1,947,291 Ford Feb. 13, 1934 2,305,415 GoflDec. 15, 1942 2,400,344 Frese May 14, 1946 FOREIGN PATENTS NumberCountry Date 13,525 Great Britain June 25. 1909 54,302 Norway Aug. 20.1934

